Wide face finishing machine using a coated abrasive



Oct. 30, 1962 H. D. GURSKY 3,060,646

WIDE FACE FINISHING MACHINE USING A COATED ABRASIVE Filed Jan. 19, 1961 2 Sheets-Sheet 1 INV EN TOR. HENRY 0- 60,9671 7 8%MMW H-D.GURSKY Oct. 30, 1962 WIDE FACE FINISHING MACHINE USING A COATED ABRASIVE 2 Sheets-Sheet 2 Filed Jan. 19, 1961 a fzna ATTORNEYS HVVENTOR HIE-WP) o. GOP-SK) States This invention relates to wide face finishing machines, and more particularly to such machines using a coated abrasive for operating on flexible sheet material.

There are several machines on the market today which sand or grind the surface of leather, fabrics, and other flexible materials, for thickness tolerance and/or finish. Among these are bufling, sueding, and wide face finishing machines in general. Such finishing machines employ a coated abrasive which is moved at high speed by means including a cylinder. In some cases the abrasive is wrapped about the cylinder, and in other cases it constitutes a relatively long endless belt, with the cylinder acting as a contact roll, while the remote end of the belt is carried by an idler roll, said idler roll being provided with an appropriate belt tensioning and belt-tracking means. The finishing machine further comprises a pressure roll which is driven at slow speed and which feeds the work in contact with the abrasive. This is mounted for precision adjustment of the spacing between the pressure roll and the abrasive, thus determining the precise thickness to which the sheet being treated is ground or finished. The finishing machine also employs a pinch roll for holding the work against the pressure roll.

It has heretofore been found that the quality of the finish and the life of the coated abrasive may be improved by providing a slight axial reciprocation of the cylinder or belt relative to the work. The cylinder (or belt) has been positively reciprocated by appropriate means such as an eccentric driven at slow speed. In the case out a belt, the mechanism is considerably more complex because it is desirable to provide axial reciprocation of the entire belt, that is, the rear portion at the idler roll as well as the forward portion at the contact roll.

A general object of the present invention is to improve wide-face finishing machines of the specified character.

A more particular object is to simplify and lighten the mechanism, which I have found may be done by reciprocating the pressure roll and the work, instead of the coated abrasive.

Still another object is to provide for or to permit reciprocation of the pinch roll with the pressure roll.

' To accomplish the foregoing general objects, and other more specific objects which will hereinafter appear, my invention resides in the abrasive finishing machine elements, and their relation one to another, as are hereinafter more particularly described in the following specification. The specification is accompanied by drawings in which:

FIG. 1 is a side elevation of an abrasive finishing machine of the belt type, embodying features of my invention; and

FIG. 2 is a section taken approximately in the plane of the bent line 22 of FIG. 1.

Referring to the drawing, and more particularly to FIG. 1, the machine comprises means including a cylinder 12 to move a coated abrasive at high speed. In the present case, the machine is of the belt type and the coated abrasive constitutes an endless belt shown at 14, with the cylinder 12 acting as a contact roll. The remote end of the belt is carried by an idler roll 16, and this may be provided with belt-tensioning means. In the present case the roll 16 is carried on a shaft 18, supported by bearings 3,050,646 Patented Oct. 30, 1962 ice 20, mounted at the ends of a horizontal yoke, one end of which is indicated at 22. The yoke is supported at its mid-point by the piston rod 24 on an air cylinder 26 whichserves to hold the belt 14 under tension. The cylinder is fixedly carried by the inner end of a frame member 28 projecting inwardly from an upright member '30.

The roll 16 also is provided with belt-tracking means. In the present case the tracking of the belt is controlled by tilting the yoke 22 and the roll 16 about the axis of the piston rod 24. For this purpose one end of the yoke 22 carries spaced fingers 32 and 34. These straddle the ends of a double-ended piston rod 36, the piston of which is movable in a generally upright cylinder 38. The cylinder preferably is operated by air. It is double-acting, and its valves are controlled by suitable tracking means. One type employs air jets at -37 directed toward movable vanes at 39, with the edge of the belt 14 normally located between the air jets and vanes. The tracking means may be conventional and requires no detailed description.

The work (the sheet material to be finished) is guided over a stationary board or table 40. It is fed by means of a pressure roll 42 which is driven at slow speed, and a pinch roll 44 which holds the work against the pressure roll 42. The work passes between the rolls 42 and 44 and then downward between the pressure roll 42 and the abrasive belt, which of course i moving at a very high speed compared to the work being treated.

The machine is provided with means for precision adjustment of the spacing between the pressure roll and the abrasive. In the present case the bearings at the ends of the pressure roll 42 are slidable on guides or ways 46, and are moved by adjusting screws which may be turned by handles 48, preferably provided with micrometer scales at 50. There is one handle at each end.

In accordance with the present invention, the pressure roll 42 is reciprocated a slight amount in axial direction.

The mechanism for this purpose is shown in FIG. 2 of the drawing, in which it will be seen that the pressure roll 42 is carried by roller bearings 52, the inner race 54 of which is axially movable for a small distance relative to the outer race 56. A thrust bearing 58 is secured at one end of the pressure roll shaft. An eccentric 60 is carried by or forms a part of the slow-speed driven shaft 62, which extends transversely of the pressure roll axis at one end of the pressure roll. A connecting rod or link 64 connects the eccentric 60 and the bearing 58, as by means of a bearing housing 66. In the present case the shaft 62 carries a pulley 68 driven by a belt 70. In this way the eccentric serves to reciprocate the pressure roll.

At its opposite end the pressure roll carries a pulley 72, which in this case is a multiple-grooved pulley, driven by multiple V-belts 74. The axial movement is small, say A maximum, and this does not affect the drive by belts 74. 7 FIG. 2 alsoshows the ways or guides 46 which aiford micrometer movement of the bearing housings 76 toward or away from the abrasive, as previously described.

Reverting to FIG. 1 the triple V-belt for driving the pressure roll is shown at 74, it being driven by a speed reduction motor 80. The belt 70 for reciprocating the pressure roll is driven by a speed reducing motor 82. The contact roll 12 is driven through multiple V-belts 84 by a main drive motor 86, and the belt tension may be varied by adjusting the height of the motor by means of adjusting screws shown at 88. Although three separate motors are shown here, it will be understood that other drive arrangements may be used.

In FIG. 1 the position of the pinch roller 44 relative to the pressure roll 42, may be adjusted by screws and 92. These are opposed, so that one screw is backed away as the other is tightened, but with both screws to- 3 gether locking the position of the arms 94 carrying the pinch roll. The arms are pivoted at 96.

Inasmuch as the reciprocation of the pressure roll 42 is intended to reciprocate the work being treated, and inasmuch as the pinch roll 44 might otherwise inhibit reciprocation of the work, I provide means so mounting the pinch roll that it is free to move axially with the pressure roll. Referring to FIG. 2, the pinch roll 44 is normally centered by compression springs 100 disposed at each end of the pinch roll. These springs accommodate the axial movement, and thus help it follow the axial movement of the pressure roll 42.

In the particular structure here shown, the pinch roll 44 is hollow and is carried between ends 102 which hold bearings 104. These are both rotatable and axially slidable on stationary bearings 106. The latter are carried on a stationary shaft 108 secured fixedly in supports 94. The shaft is locked in the supports by means of set screws 112. The fixed shaft 108 has collars 114 which hold the springs 100 against axial movement. At their inner ends the springs bear against thrust washers 116. Lubrication may be supplied through connections at 118.

With this arrangement the pinch roll is an idler roll which is free to rotate and free to oscillate somewhat in axial direction, but which is normally self-centered by the springs.

In some ways the belt grinder here shown resembles that disclosed in a copending application of Louis J. Hine, Serial No. 58,829, filed September 27, 1960, and entitled, Belt Grinder. The said application discloses an improved and convenient means for facilitating replacement of the abrasive belt 14 when worn. For this purpose the bearing at one end of the contact roll 12 is releasable by means of quick acting clamps, as in said application. The hearing at the other end of the contact roll is a tiltable hearing, as in said application. The shaft at is outer end, well beyond the tiltable bearing and the drive belt 84, is provided with a generally upright power cylinder, in this case an air cylinder 120, which is pivotally anchored at 122, and the piston rod 124 of which is connected to a yoke 126 which is pivotally connected to a bearing housing 128 on the end of the contact roll shaft. In this way the remote end of the contact roll may be raised and moved rearward by means of air cylinder 120. This facilitates removal of a worn belt and replacement by a new belt, following which the contact roll may be restored to initial position, and the remote releasable bearing again clamped in position.

In the machine of said copending application the contact roll 12 is axially oscillated. The mechanism for oscillating the contact roll is arranged to accommodate tilting of the contact roll, and indeed the entire oscillating mechanism is bodily tilted with the contact roll. The present machine obviously is simpler because the tilting of the contact roll in no way affects the oscillating mech anism for the pressure roll.

There are additional advantages in oscillating the work as here shown, rather than the abrasive. An abrasive covered cylinder, or an abrasive belt with contact roll and idler roll, are relatively large and heavy. A cylinder may weigh from 1000 to 2000 pounds, depending on its size. A contact roll together with its idler may weigh even more. In either case, the cylinder or contact roll turns at fairly high speed, say, 1200 to 1500 r.p.m.

In contrast with this the pressure roll weighs only say 300 pounds, and rotates at a slow speed of from say 5 to 50 rpm. The inertia of oscillation therefore is much less than for the cylinder. This means that there is a great reduction in the force needed for oscillation, and consequently in the size of the oscillating mechanism. There is also reduced reaction force on the machine frame, and increased life expectancy for the various moving parts. In the case of a belt machine, the bearings required for the contact roll and the idler roll may be smaller and simpler because they do not need to provide oscillation. The large roller bearings provided by Hine for the contact roll and the idler roll may be replaced with precision ball-bearings which are smaller, smoother running, and lower in cost. There is no disadvantage from the viewpoint of the operator feeding the work, because he feeds the work over the stationary work board or table 40, and is not bothered by the oscillation of the feed rolls.

The speed of oscillation may be adjusted to suit the operator, based on his experience with the particular material being treated. In the example here illustrated the feed roll is oscillated 200 cycles per minute, and the span of oscillation is inch. The bearings for the pinch roll 44 afford axial movement, and are preferably designed to permit twice as much travel as the oscillation of the pressure roll 42, or in the present case a travel of /2 inch. This is a precaution in case the pressure roll happens to be all the way over at one end of its oscillating stroke when the pinch roll is engaged by the work.

The adjustment of the pinch roll by means of the screws and 92 is such as to leave a slight gap between the pinch roll and the pressure roll. This gap usually is less than the gap between the pressure roll and the abrasive. When work is not passing through the machine the pinch roll is free to center itself. When work is passing through the machine, the pinch of the work between the floating pinch roll and the mechanically oscillated pressure roll, results in the bodily oscillation as a single unit of all three (meaning the two rolls and the work therebetween).

It is believed that the construction and operation of my improved Wide face finishing machine, as well as the advantages thereof, will be apparent from the foregoing detailed description. It will also be apparent that while I have shown and described the invention in a preferred form, changes may be made in the structure shown, without departing from the scope of the invention as sought to be defined in the following claims.

I claim:

1. A wide face finishing machine comprising means including a rotatable cylinder to move a coated abrasive, a pressure roll for feeding work in contact with the abrasive, a pinch roll for holding the Work against the pressure roll, means to rotate the cylinder at high speed, means to drive the pressure roll at low speed, and means to reciprocate the pressure roll a slight amount in axial direction relative to the cylinder.

2. A wide face finishing machine comprising means including a rotatable cylinder to move a coated abrasive, a pressure roll for feeding work in contact with the abrasive, a pinch roll for holding the work against the pressure roll, means to rotate the cylinder at high speed, means to drive the pressure roll at low speed, means affording precision adjustment of the spacing between the pressure roll and the abrasive, and means to reciprocate the pressure roll a slight amount in axial direction relative to the cylinder.

3. A wide face finishing machine comprising means including a rotatable cylinder to move a coated abrasive, a pressure roll for feeding work in contact with the abrasive, a pinch roll for holding the work against the pressure roll, means to rotate the cylinder at high speed, means to drive the pressure roll at low speed, means to reciprocate the pressure roll a slight amount in axial direction relative to the cylinder, and means so mounting the pinch roll that it is free to oscillate axially with the pressure ro 4. A wide face finishing machine comprising means including a rotatable cylinder to move a coated abrasive, a pressure roll for feeding work in contact with the abrasive, a pinch roll for holding the Work against the pressure roll, means to rotate the cylinder at high speed, means to drive the pressure roll at low speed, means affording precision adjustment of the spacing between the pressure roll and the abrasive, means to reciprocate the pressure roll a slight amount in axial direction relative to the cylinder, and means so mounting the pinch roll that it is free to oscillate axially with the pressure roll.

5. A wide face finishing machine as defined in claim 1 in which the means for reciprocating the pressure roll in axial direction comprises an eccentric carried by a slow speed driven shaft extending transversely of the pressure roll axis, and means so operatively connecting the eccentric and the roll that the eccentric causes reciprocation of the roll without interfering with rotation of the roll.

6. A wide face finishing machine as defined in claim 2 in which the means for reciprocating the pressure roll in axial direction comprises an eccentric carried by a slow speed driven shaft extending transversely of the pressure roll axis at one end of the pressure roll, a bearing at one end of the pressure roll, and a connecting rod so connecting the eccentric and the bearing that the eccentric causes reciprocation of the pressure roll.

7. A wide face finishing machine as defined in claim 3 in which the means for reciprocating the pressure roll in axial direction comprises an eccentric carried by a slow speed driven shaft extending transversely of the pressure roll axis at one end of the pressure roll, a hearing at one end of the pressure roll, and a connecting rod so connecting the eccentric and the bearing that the eccentric causes reciprocation of the pressure roll.

8. A wide face finishing machine as defined in claim 3 in which the pressure roll is carried by self-aligning roller bearings, the inner race of which is axially movable for a small distance relative to the outer race, and in which the means for reciprocating the pressure roll in axial direction comprises an eccentric carried by a slow speed driven shaft extending transversely of the pressure roll axis at one end of the pressure roll, a bearing at one end of the pressure roll, and a connecting rod so connecting the eccentric and the bearing that the eccentric causes reciprocation of the pressure roll.

9. A wide face finishing machine as defined in claim 7 in which the pinch roll is mounted for axial movement, and in which it is normally centered by compression springs disposed at the ends of the pinch roll, said springs accommodating axial movement of the pinch roll to help it follow the axial movement of the pressure roll.

10. A wide face finishing machine as defined in claim 3 in which the pinch roll is mounted for axial movement, and in which it is normally centered by compression springs disposed at the ends of the pinch roll, said springs accommodating axial movement of the pinch roll to help it follow the axial movement of the pressure roll.

11. A wide face finishing machine as defined in claim 4 in which the pinch roll is mounted for axial movement, and in which it is normally centered by compression springs disposed at the ends of the pinch roll, said springs accommodating axial movement of the pinch roll to help it follow the driven axial movement of the pressure roll.

12. A wide face finishing machine as defined in claim 1 in which the coated abrasive is in the form of an endless belt, and in which the cylinder acts as a contact roll, and in which the remote end of the belt is carried by an idler roll, said idler roll being provided with belt tensioning and belt tracking means.

13. A Wide face finishing machine as defined in claim 2 in which the coated abrasive is in the form of an endless belt, and in which the cylinder acts as a contact roll, and in which the remote end of the belt is carried by an idler roll, said idler roll being provided with belt tensioning and belt tracking means.

14. A wide face finishing machine as defined in claim 3 in which the coated abrasive is in the form of an endless belt, and in which the cylinder acts as a contact roll, and in which the remote end of the belt is carried by an idler roll, said idler roll being provided with belt tensioning and belt tracking means.

References Cited in the file of this patent UNITED STATES PATENTS 1,936,991 Pinkney Nov. 28, 1933 1,995,382 Fenton Mar. 26, 1935 2,637,949 De Bay May 12, 1953 2,876,600 Pendergast Mar. 10, 1959 

